[ApK]

I usually start with a title (or lede line.)
Unfortunately, I often stop there, too. :-(

Anythewho...

I do think you need to settle on something before publishing, and then leave it alone. At worst, after a decently long period observing sales and comments, you could always 'reissue' with a new cover and a new title as many books do (like the ones that are turned into movies....) and a notation that says "originally published as..."

If you are self-editing, you at least have to put your finished manuscript away for while so it's not fresh in your mind and then re-read it.
THAT should be the time when a particularly evocative phrase or image will stand out to you as a good title.

ApK

p.s. in reading some of your responses here, I feel compelled to point out that you solicited advice on how to encourage readership of this particular work of yours on a public Internet forum.
I don't see anything particularly offensive or disrespectful in the responses.
If you disagree, and whether anyone read the whole work or not is irrelevant.
They see what any prospective reader would see and are telling you what it communicates to them.
Whether you see those comments as constructive or not, in these conditions you might want to limit any reply to something like "Thank you for your opinion" and leave it at that.